DIY DC power cables

[tapatrick]

16 hours ago, Cornan said:

 

I would actually say that the original Regen is really good. I was a bit dissapointed on ISO Regen until I added the Luckit BluWave USB to Spdif post it. Now I would'nt trade the IR+USPCB+BluWave for anything. A massive improvement! ?

 

Yes, I second that regarding the ISO R, USPCB and Bluewave, a magic combo...:)

[BigGuy]

13 hours ago, JohnSwenson said:

I've been doing measurements of this, they show that at least for digital circuits, the inductance of the cable is probably more important than the raw DC resistance. Many digital devices do not draw a continuous current, the load can fluctuate rapidly and by a fair amount. The impedance of the cable at the higher frequencies (above line frequency) can be significant. A piece of 14 AWG romex  has a much higher impedance than a 20AWG starquad.

 

When I started measuring all this I was rather stunned by how much impedance regular cables add the higher load frequencies. The results at the load are MANY MANY times worse than the regulator itself. Starquad has 9 times lower inductance than zipcord, that makes a big difference, even for short cables.

 

I haven't done much checking of different connector types so I'm not sure about that.

 

This is all happening now since I got my power supply impedance tester up and running last week, but I found out it wasn't even good enough. I now have to build a differential preamp for it in order to be able to properly measure the impedance of the regulator. At the end of a cable works fine, but when measuring the impedance of the regulator the voltage drop across across the output jack ground causes massive ground loops in the measurement system that totally destroys any accuracy. So yet again I need to build a high impedance low noise differential amp to measure, of all things, power supplies! I'm glad I can build these myself for less than $100, the commercial ones go for $8000, and are $1500 used on ebay.

 

John S.

I am a bit confused, John.

You mention "...for digital circuits, the INDUCTANCE of the cable is probably more important than DC resistance."

Then you mention that 20AWG starquad is lower IMPEDANCE than 14AWG Romex.

The parameters IMPEDANCE and INDUCTANCE are both mentioned in the next paragraph.

Related parameters appear to be RESISTANCE and REACTANCE.

Doing a bit of reading which confused me a bit more, it appears that some of these terms are used for AC circuits and the others for DC.

Is there a simplified way for me, etal., to understand these terms?

Am I correct in the "take away" being that star quad would be the preferred way to make DC power cables?

Then, JSGT of course.

[Cornan]

3 hours ago, tapatrick said:

Yes, I second that regarding the ISO R, USPCB and Bluewave, a magic combo...:)

 

It was all thanks to you that I now is enjoying both BluWave and LT3045s. They have vastly improved my setup. ?

[charlesphoto]

Speaking of soldering dc cable connectors, I was wondering if anyone has just soldered a ground wire shunt directly to the negative post of a dc plug, and if that has any bearing on sound quality by then bypassing the screw adapters? 

 

I’ve got a soldering kit and holder coming as a stocking stuffer so curious to try my hand at soldering. Will practice on low level/throwaway items first of course, but got me to thinking - why not just solder that thin gauge ground wire directly?

[John769]

48 minutes ago, Cornan said:

 

It was all thanks to you that I now is enjoying both BluWave and LT3045s. They have vastly improved my setup. ?

 Ditto the latter.  Thanks to both of you !    (and Rob)

[JohnSwenson]

6 hours ago, BigGuy said:

I am a bit confused, John.

You mention "...for digital circuits, the INDUCTANCE of the cable is probably more important than DC resistance."

Then you mention that 20AWG starquad is lower IMPEDANCE than 14AWG Romex.

The parameters IMPEDANCE and INDUCTANCE are both mentioned in the next paragraph.

Related parameters appear to be RESISTANCE and REACTANCE.

Doing a bit of reading which confused me a bit more, it appears that some of these terms are used for AC circuits and the others for DC.

Is there a simplified way for me, etal., to understand these terms?

Am I correct in the "take away" being that star quad would be the preferred way to make DC power cables?

Then, JSGT of course.

OK, really quick and dirty primer. (not terribly accurate, no formulas, but hopefully gets the idea across)

 

Resistance is a property of conductors that tends to impede the flow of electricity. Resistance is usually defined as a DC property. It is measured in ohms.

 

Impedance is a frequency dependent equivalent to resistance. It is not a single number, it is of the form: ohms at a specific frequency. You can either specify it at specific frequencies or have a graph that plots ohms VS frequency.

 

Reacatnce is much more complicated, it is what gives rise to impedance. There are two types of reactance: capacitive and inductive. Capacitive is created by electric fields and inductive is created by magnetic fields. They behave oppositely to each other, at a given frequency increasing inductance increases impedance, increasing capacitance decreases impedance. For a given value of inductance increasing frequency increases impedance, for a given value of capacitance increasing frequency decreases impedance.

 

Every real circuit has a combination of resistance, inductance and capacitance. It is the interplay between these that give rise to how circuits behave.

 

The reality is way more complicated involving phase as well, butI'm leaving all that out to cover the very basic properties.

 

John S.

 

[Ralf11]

how about:  Impedance is the AC version of resistance.  Impedance usually needs to be considered in the real world as most signals (and noise) are AC, not DC

 

AC in the broader sense of a signal where the voltage varies over time, not just 50 or 60 Hz ...

 

 

 

 

[Cornan]

16 hours ago, charlesphoto said:

Speaking of soldering dc cable connectors, I was wondering if anyone has just soldered a ground wire shunt directly to the negative post of a dc plug, and if that has any bearing on sound quality by then bypassing the screw adapters? 

 

I’ve got a soldering kit and holder coming as a stocking stuffer so curious to try my hand at soldering. Will practice on low level/throwaway items first of course, but got me to thinking - why not just solder that thin gauge ground wire directly?

 

I haven't tried to solder the JSGT, but I know that external ground improves with better connection (better surface contact and as close to the source as possible). A good executed soldered connection should be a very good option if done right. 

[sandyk]

16 minutes ago, Cornan said:

 

I haven't tried to solder the JSGT, but I know that external ground improves with better connection (better surface contact and as close to the source as possible). A good executed soldered connection should be a very good option if done right. 

 It may be easier, as well as readily reversible if Service is needed, to solder the wire to a solder lug, clean the anodising etc. away from the area where you intend to connect it and use a nut and bolt to secure it. e.g.

https://www.ebay.com.au/itm/NEW-Solder-Lugs-Pk-50-HP1350/253255370305?epid=903989410&hash=item3af7324641:g:-tUAAOSwzppaEId5

In the case of an item with a spare (unused) RCA socket,(STB etc.)  you can solder the earth  wire to the "earth" side of an RCA plug, and plug it in. 

[Cornan]

8 minutes ago, sandyk said:

 It may be easier, as well as readily reversible if Service is needed, to solder the wire to a solder lug, clean the anodising etc. away from the area where you intend to connect it and use a nut and bolt to secure it. e.g.

https://www.ebay.com.au/itm/NEW-Solder-Lugs-Pk-50-HP1350/253255370305?epid=903989410&hash=item3af7324641:g:-tUAAOSwzppaEId5

In the case of an item with a spare (unused) RCA socket,(STB etc.)  you can solder the earth  wire to the "earth" side of an RCA plug, and plug it in. 

 

That would work. However, keep in mind that using RCA as a ground point can be very inconsistent IME. Make sure to try several RCA sockets if possible, ie. left analogue, right analogue and Spdif digital. 

[sandyk]

3 minutes ago, Cornan said:

 

That would work. However, keep in mind that using RCA as a ground point can be very inconsistent IME. Make sure to try several RCA sockets if possible, ie. left analogue, right analogue and Spdif digital. 

 

 Provided that a good fitting RCA plug is used there should be no inconsistency.

 If you doubt this, use your DMM to read the resistance between the earth sides of several sockets, where you are unlikely to find more than a fraction of 1 ohm difference.

[Forehaven]

On 12/15/2017 at 5:52 PM, sandyk said:

 

That isn't always strictly true. That's why power transmission lines use very high voltages, and transformers later on to step down the voltages again.

My own take on DC leads,  is that provided the Output Impedance of the voltage Regulator etc. is VERY low, that a 2 foot length from say a piece of 2 core 7.5A mains cable scrounged from a redundant lead will be close to as good as it gets, without any fancy tinkering that you guys (and John S.) talk about.

Other than the reliability factor, neither should it matter about using fancy and expensive DC plugs, especially if those used are of the lockable type. Some Microphone plugs and sockets make fine DC connectors. 

e.g.

http://www.altronics.com.au/p/p0953-2-pin-male-chassis-mount-microphone-connector/

All very confusing to me Sandy, using simple Canare starquad with screw terminals and those mic connectors, what is the max length I can get away with?  What are the symptoms of a too long a length cable...dropouts/lower SI?

[BigGuy]

I would also be interested in knowing how short a starquad umbilical can be before it does not make sense.  In my case, I have an NOS brick style LPS which happens to have a 5V output.  I grafted on a barrel connector Digitek pigtail that is 6' long so overall DC cable length is about 8'.  Based on what I have read here, I would like to potentially improve the power quality to my target device by either (1) trimming the existing graft to 12-24 inches so I still have placement leeway or (2) replacing the graft with a similar length of starquad umbilical, perhaps with an Oyaide (or other recommendation?) barrel connector.

 

The other question in my mind is whether this umbilical treatment makes sense with an LPS as described?

 

Probably already discussed ad nauseam but does a JSSG make sense on these DC cables?

[sandyk]

5 hours ago, Forehaven said:

All very confusing to me Sandy, using simple Canare starquad with screw terminals and those mic connectors, what is the max length I can get away with?  What are the symptoms of a too long a length cable...dropouts/lower SI?

 

 Unfortunately, I will have to let John answer that one !

I keep all my DC  leads as short as possible using mains cable pieces for their copper content (gauge)  to reduce inductance, and possible RF/EMI pickup..

[Cornan]

11 hours ago, sandyk said:

 

 Provided that a good fitting RCA plug is used there should be no inconsistency.

 If you doubt this, use your DMM to read the resistance between the earth sides of several sockets, where you are unlikely to find more than a fraction of 1 ohm difference.

 

The inconsistence of RCA plugs is purely based on my own experience using my own ears to guide me. I do not know why it is inconsistent. I only know that I have tried it a lot on different devices. It could be due to distance, ie. that the RCA closest to common ground sounds best. It could also be that digital devices should be grounded to Spdif digital and analogue devices to analogue RCA. I don't actually know, but recommend that one try different RCA sockets, since it an easy thing to do. Just a unplug, plug-in and listen! ?

 

[Cornan]

1 hour ago, BigGuy said:

Probably already discussed ad nauseam but does a JSSG make sense on these DC cables?

 

It shouldn't, but to me it does! Ghent DC Canare 4S6 cables with JSSG sounds better than DIY Canare 4S6. ATL starquad DC cables with JSSG sounds the same as Ghent JSSG.

[lmitche]

2 hours ago, Cornan said:

 

It shouldn't, but to me it does! Ghent DC Canare 4S6 cables with JSSG sounds better than DIY Canare 4S6. ATL starquad DC cables with JSSG sounds the same as Ghent JSSG.

Same thing here, JSSG on dc power cables yields a nice improvement and is cumulative as more cables are treated.

 

I expect to try treat and listen to an AC cable treated with JSSG tomorrow.

[jamesg11]

On 17/12/2017 at 8:09 AM, JohnSwenson said:

OK, really quick and dirty primer. (not terribly accurate, no formulas, but hopefully gets the idea across)

 

Resistance is a property of conductors that tends to impede the flow of electricity. Resistance is usually defined as a DC property. It is measured in ohms.

 

Impedance is a frequency dependent equivalent to resistance. It is not a single number, it is of the form: ohms at a specific frequency. You can either specify it at specific frequencies or have a graph that plots ohms VS frequency.

 

Reacatnce is much more complicated, it is what gives rise to impedance. There are two types of reactance: capacitive and inductive. Capacitive is created by electric fields and inductive is created by magnetic fields. They behave oppositely to each other, at a given frequency increasing inductance increases impedance, increasing capacitance decreases impedance. For a given value of inductance increasing frequency increases impedance, for a given value of capacitance increasing frequency decreases impedance.

 

Every real circuit has a combination of resistance, inductance and capacitance. It is the interplay between these that give rise to how circuits behave.

 

The reality is way more complicated involving phase as well, butI'm leaving all that out to cover the very basic properties.

 

John S.

 

Appreciated, John  - ‘q&d primers’ are what I need, so feel free to drop them in regularly ...!

/& I do need to re-read them regularly, whenever the terminology re-presents, to minimise my getting confus-ed ...

 

[sandyk]

9 hours ago, BigGuy said:

I would also be interested in knowing how short a starquad umbilical can be before it does not make sense.  In my case, I have an NOS brick style LPS which happens to have a 5V output.  I grafted on a barrel connector Digitek pigtail that is 6' long so overall DC cable length is about 8'.  Based on what I have read here, I would like to potentially improve the power quality to my target device by either (1) trimming the existing graft to 12-24 inches so I still have placement leeway or (2) replacing the graft with a similar length of starquad umbilical, perhaps with an Oyaide (or other recommendation?) barrel connector.

 

The other question in my mind is whether this umbilical treatment makes sense with an LPS as described?

 

Probably already discussed ad nauseam but does a JSSG make sense on these DC cables?

 

It seems to me, that if your DC supply leads were fairly long, that it might be a good idea to take this further and use an additional wire along with a Kelvin Sensor as John Swenson has provided as an option for his JS2 PSU .

This would of course necessitate a special kind of PSU.Some Voltage Regulators do however  permit the use of Kelvin Sensing.

 

 Does this seem worthwhile to you John or Alex C ?

 Perhaps an idea for a future Uptone general purpose PSU ?

[Cornan]

6 hours ago, lmitche said:

Same thing here, JSSG on dc power cables yields a nice improvement and is cumulative as more cables are treated.

 

I expect to try treat and listen to an AC cable treated with JSSG tomorrow.

 

If you have'nt tried JSSG on USB cables yet I can recommend it! ?Ethernet is great with JSSG too, but I guess you've done it already? So far my ac power cables are mostly starquad which is cumulative throughout in my setup. I have'nt tried JSSG on them yet so I would appreciate if you could post back your impressions when you've tried.

 

[Cornan]

1 hour ago, sandyk said:

 

It seems to me, that if your DC supply leads were fairly long, that it might be a good idea to take this further and use an additional wire along with a Kelvin Sensor as John Swenson has provided as an option for his JS2 PSU .

This would of course necessitate a special kind of PSU.Some Voltage Regulators do however  permit the use of Kelvin Sensing.

 

 Does this seem worthwhile to you John or Alex C ?

 Perhaps an idea for a future Uptone general purpose PSU ?

 

I have external (boxed) shunt regulators with starquad Kelvin cables and Kelvin plugs on order that I will try post my ISO Regen and Aqvox switch in a couple of months or so. I will compare it to my LT3045s in series that I use on these spots as soon as I have received them. ?

So far ATLs shunt regulators are only suitable for roughly <480mA, but he's working on a <1.5A shunt regulator as well.

[lmitche]

5 hours ago, Cornan said:

 

If you have'nt tried JSSG on USB cables yet I can recommend it! ?Ethernet is great with JSSG too, but I guess you've done it already? So far my ac power cables are mostly starquad which is cumulative throughout in my setup. I have'nt tried JSSG on them yet so I would appreciate if you could post back your impressions when you've tried.

 

Thanks Cornan, and yes, I did the JSSG treatment on the data carrying USB and Ethernet cables first. 

[BigGuy]

On 12/16/2017 at 4:09 PM, JohnSwenson said:

OK, really quick and dirty primer. (not terribly accurate, no formulas, but hopefully gets the idea across)

 

Resistance is a property of conductors that tends to impede the flow of electricity. Resistance is usually defined as a DC property. It is measured in ohms.

 

Impedance is a frequency dependent equivalent to resistance. It is not a single number, it is of the form: ohms at a specific frequency. You can either specify it at specific frequencies or have a graph that plots ohms VS frequency.

 

Reacatnce is much more complicated, it is what gives rise to impedance. There are two types of reactance: capacitive and inductive. Capacitive is created by electric fields and inductive is created by magnetic fields. They behave oppositely to each other, at a given frequency increasing inductance increases impedance, increasing capacitance decreases impedance. For a given value of inductance increasing frequency increases impedance, for a given value of capacitance increasing frequency decreases impedance.

 

Every real circuit has a combination of resistance, inductance and capacitance. It is the interplay between these that give rise to how circuits behave.

 

The reality is way more complicated involving phase as well, butI'm leaving all that out to cover the very basic properties.

 

John S.

 

Thanks for the explanation, John.  Enough detail for me!

[BigGuy]

12 hours ago, Cornan said:

 

If you have'nt tried JSSG on USB cables yet I can recommend it! ?Ethernet is great with JSSG too, but I guess you've done it already? So far my ac power cables are mostly starquad which is cumulative throughout in my setup. I have'nt tried JSSG on them yet so I would appreciate if you could post back your impressions when you've tried.

 

Just read contents of this thread which seems to have ended...

 

http://jplay.eu/forum/index.php?/topic/1128-can-the-guys-whove-used-emirfi-paper-sotm-3m-etc-post-photos-here-of-how-you-did-it/page-4

 

What does anyone think about putting an "air spacer", cotton sleeve or polyethylene foam tube <http://www.thefoamfactory.com/closedcellfoam/polyethylene.html>

(scroll down to near bottom) around the DC, USB, etc., cable before shielding? 

The tube might need to be split to avoid issues with terminations.  Certainly prices are reasonable.

 

Not sure where anyone is buying braid but did locate on Amazon...

 

https://www.amazon.com/Tubular-Copper-Bright-Diameter-Length/dp/B003R501TA/ref=sr_1_1?s=music&ie=UTF8&qid=1513612475&sr=8-1&keywords=tubular+copper+braid

 

Not sure whether tin plated is "better" than copper but I prefer the latter aesthetically and it is pretty easy to create a solder pad for attaching the ground wire...just put something that does not melt or burn inside the braid tube.

[Cornan]

1 hour ago, BigGuy said:

Just read contents of this thread which seems to have ended...

 

http://jplay.eu/forum/index.php?/topic/1128-can-the-guys-whove-used-emirfi-paper-sotm-3m-etc-post-photos-here-of-how-you-did-it/page-4

 

What does anyone think about putting an "air spacer", cotton sleeve or polyethylene foam tube <http://www.thefoamfactory.com/closedcellfoam/polyethylene.html>

(scroll down to near bottom) around the DC, USB, etc., cable before shielding? 

The tube might need to be split to avoid issues with terminations.  Certainly prices are reasonable.

 

Not sure where anyone is buying braid but did locate on Amazon...

 

https://www.amazon.com/Tubular-Copper-Bright-Diameter-Length/dp/B003R501TA/ref=sr_1_1?s=music&ie=UTF8&qid=1513612475&sr=8-1&keywords=tubular+copper+braid

 

Not sure whether tin plated is "better" than copper but I prefer the latter aesthetically and it is pretty easy to create a solder pad for attaching the ground wire...just put something that does not melt or burn inside the braid tube.

 

Not sure why you want to add a polyethylene foam tube before (inside) the shielding? IMO if you want to add a shock absorber you probably want it after (around) the shielding. I would have the JSSG as close to the wires as possible for best results. Remember that JSSG acts like a Faraday cage for cables. You want to keep all the electromagnetic fields close to and inside the JSSG. Adding too much space inbetween might give it an escape route through the air spacer. I think you want to avoid it as much as possible. My two cents ofcourse.

 

My Ghent DC cables have copper braid and my ATL have tinned braid. I have'nt detected any difference, but copper braid looks nicer! ? With that said silver plated braid sounds noticable better on coaxial cables IME. Not sure if it will matter much on JSSG though.